This invention relates to an improved method for manufacture of jelly gum confections employing enzymatically debranched starches. This invention also relates to confections made by this method.
Jelly gum confections ("confections") are characterized by a translucent, resilient gel structure. These confections include gum drops, gum slices (sugared jellies), jujubes (hard gums), fruit gums (imitation fruit pieces) and jelly beans.
Starch is typically used to form the gel that is characteristic of these confections. In addition to a starch or starch blend, confection formulations include one or more sweeteners, water, flavoring, coloring and other confectionery ingredients.
These confections are manufactured by blending the ingredients, heating an aqueous dispersion of the starch, with or without the other ingredients, to the point where the starch becomes completely gelatinized, and molding or extruding the hot blend to form the confection pieces. The pieces may be coated with sugar, starch, oil or other ingredients to produce the finished confection.
For many years, these confections were molded by the starch cast mold method ("Mogul system"). In this method, the hot liquid confection is deposited into molds formed in a bed of dry starch. Disadvantages inherent in this method, such as long gel setting and drying times, high temperature heating requirements and starch cast mold handling problems, led to the development of alternative methods and formulations.
For example, U.S. Pat. No. 4,225,627 to Moore describes a starchless molding method which uses steam to release confection from their molds.
U.S. Pat. No. 3,265,509 to Wurzburg, et al. describes an extrusion process for manufacture of confections employing a high amylose starch.
U.S. Pat. No. 4,567,055 to Moore describes the development of extrusion processes for manufacture of confections and sets forth an improvement thereon.
Others have suggested modifications in the confection formulation to improve the process and the quality of the gel in the finished confection. U.S. Pat. No. 3,218,177 to Robinson, et al teaches the use of a starch consisting essentially of amylose and amylopectin in a ratio of 75:25 to 40:60. In using this type of starch, a starch slurry must be heated to at least 135.degree. C., and preferably 140.degree.-165.degree. C., to obtain the complete starch gelatinization which is essential to the manufacture of an acceptable confection.
U.S. Pat. No. 3,446,628 to Schoch, et al teaches the use of a solvent-defatted, thin-boiling starch with a fluidity range of 30 to 80 and an amylose content not in excess of 35%. It is claimed that this starch sets quickly in to a gel and forms an acceptable confection after heating to 129.degree.-135.degree. C. for 26-28 seconds with a steam injection cooker. The disadvantage of this method is that the starch must be treated with a solvent to remove fat.
U.S. Pat. No. 4,726,957 to Lacourse, et al teaches the use of an acid-or enzyme-converted high amylose starch in these confections. Alphaamylase enzyme is employed for the enzyme conversion of the starch. This starch provides low hot viscosity and acceptable gel set time in addition to the desirable gel character of high amylose starch. However, a high temperature, pressurized cooking process is required to gelatinize the starch.
In spite of these attempts to improve traditional confection manufacturing, there remains a need for efficient methods which do not compromise confection quality.
It is well known that high amylose starches yield a more desirable gel strength and texture in these confections, particularly when the formulation contains a blend of the high amylose starch and a thin-boiling starch. However, the hot viscosity of the starch tends to increase to an undesirable level when high amylose starch is used, and high temperature cooking is required to gelatinize the starch.
Furthermore, high amylose starches are obtained from special hybrids of corn, barley and pea which contain as much as 70% amylose, and are more expensive and more difficult to isolate or handle than the starches from readily available sources such as corn, potato, wheat, rice, tapioca and the like. Most of the readily available starches contain less than 30% amylose.
Starch is a polysaccharide typically comprising a mixture of about 20-25% amylose and about 75-80% amylopectin which is organized into compact granular structures. Amylose is a linear polymer of D-anhydroglucose units which are linked by alpha-1,4-D-glucosidic bonds. Amylopectin is a large branched polymer of amylose chains linked by alpha-1,6-D-gluocosidic bonds in a tree-like structure. Depending upon the variety of plant from which the starch is obtained, amylose ordinarily contains between 250 and 12,500 D-anhydroglucose units and amylopectin contains between 400,00 and 3,125,000 D-anhydroglucose units.
In this invention, a starch containing a high percentage of short chain amylose (i.e., amylose of a molecular weight of no more than 20,000 measured against dextran standards by gel permeation chromatography) is produced from any of the readily available amylopectin-containing starches by treating the starch with an enzyme capable of cleaving the alpha-1,6-D-glucosidic linkages of the amylopectin. This enzymatic treatment cleaves the branch points in the amylopectin molecule, yielding a mixture of short chain amylose and partially debranched amylopectin, together with any remaining amylopectin or any long chain amylose present in the untreated starch.
In addition to providing functional properties similar to a high amylose starch (e.g., gel strength), this debranched starch mixture also improves the quality of the confection gel, provides low hot viscosity during processing, and required lower cooking temperatures than high amylose starch.
Thus, it is an object of this invention to provide jelly gum confections and a method of their manufacture employing starches which possess the desirable gel properties of a high amylose starch, but do not require high temperature cooking nor exhibit the high hot viscosity of high amylose starch. These properties are advantageously provided by a starch which has been enzymatically debranched.